From dd369b451a24ed62d31007b1ec4b35a730c73b2f Mon Sep 17 00:00:00 2001
From: Kruti Shah <krutis0201@gmail.com>
Date: Thu, 20 Feb 2025 02:03:06 +0530
Subject: [PATCH] heap implementation

---
 .../hithomelabs/princeton1/module8/Heap.java    | 17 ++++++++++++++---
 .../princeton1/module8/HeapSort.java            |  8 +++++++-
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/module8/src/main/java/com/hithomelabs/princeton1/module8/Heap.java b/module8/src/main/java/com/hithomelabs/princeton1/module8/Heap.java
index b728767..f439091 100644
--- a/module8/src/main/java/com/hithomelabs/princeton1/module8/Heap.java
+++ b/module8/src/main/java/com/hithomelabs/princeton1/module8/Heap.java
@@ -14,10 +14,23 @@ public class Heap{
     * * Implement sink API to sink a node if it's sub-heap is not heap-order
     */
     public static <T> void sink(T[] arr, int root, int N){
+        while (N >= root*2) {
+            int greater_index = root * 2;
+            if (N >= root * 2 + 1 && less(arr[root * 2], arr[root * 2 + 1]))
+                greater_index += 1;
+            if(!less(arr[root], arr[greater_index]))
+                break;
+            exch(arr, root, greater_index);
+            root = greater_index;
+        }
     }
 
     // * * Swim if element is not root, and parent is lesser than node
-    public static <T extends Comparable<T>> void swim(T[] arr, int node, int N){
+    public static <T> void swim(T[] arr, int node){
+        while(node > 1 && less(arr[node/2], arr[node])){
+            exch(arr, node, node/2);
+            node = node/2;
+        }
     }
 
     private static <T> void exch(T[] arr, int i, int j){
@@ -30,6 +43,4 @@ public class Heap{
         if(((Comparable<T>)v).compareTo(w) < 1 ) return true;
         else return false;
     }
-
-
 }
diff --git a/module8/src/main/java/com/hithomelabs/princeton1/module8/HeapSort.java b/module8/src/main/java/com/hithomelabs/princeton1/module8/HeapSort.java
index 55d7b91..b4ec4e0 100644
--- a/module8/src/main/java/com/hithomelabs/princeton1/module8/HeapSort.java
+++ b/module8/src/main/java/com/hithomelabs/princeton1/module8/HeapSort.java
@@ -2,7 +2,6 @@ package com.hithomelabs.princeton1.module8;
 
 import com.hithomelabs.princeton1.module5.AbstractCustomSorts;
 
-
 public class HeapSort<E> extends AbstractCustomSorts<E> {
 
     @Override
@@ -23,5 +22,12 @@ public class HeapSort<E> extends AbstractCustomSorts<E> {
      * * P.S the provision of making the index 0 null for ease of use has already been done above
     */
     private void coreSortingLogic(E[] arr, int N) {
+        for(int n=2; n <= N; n++){
+            Heap.swim(arr, n);
+        }
+        while (N > 1){
+            exch(arr, 1, N--);
+            Heap.sink(arr, 1, N);
+        }
     }
 }